Genentech Presents Positive Phase III Study Results for One-dose Xofluza (Baloxavir Marboxil) in Children With the Flu

September 2, 2019 |

8 min read

Genentech, a member of the Roche Group, announced that the Phase III MINISTONE-2 study showed that one-dose Xofluza™ was a well-tolerated and effective potential treatment for the flu in otherwise healthy children aged one to less than 12 years old.

Sept. 2, 2019 05:00 UTC

Phase III MINISTONE-2 data are consistent with known safety profile of Xofluza in children and show comparable efficacy to oseltamivir
Xofluza was administered as a one-dose oral suspension, a potentially more convenient treatment option for children
Children are at high risk of developing the flu, and complications lead to approximately one million children under five years old being hospitalized globally every year

SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)-- Genentech, a member of the Roche Group (SIX: RO, ROG; OTCQX: RHHBY), today announced that the Phase III MINISTONE-2 study showed that one-dose Xofluza™ (baloxavir marboxil) was a well-tolerated and effective potential treatment for the flu in otherwise healthy children aged one to less than 12 years old. The study met its primary endpoint, which evaluated the proportion of patients with adverse events (AEs) or severe AEs up to study day 29, demonstrating results consistent with the safety profile of Xofluza. In Xofluza-treated participants, 46.1 percent experienced at least one treatment-emergent AE compared to 53.4 percent in the oseltamivir arm. The study also showed the efficacy of Xofluza to be comparable to oseltamivir (a proven effective treatment for children with the flu). In addition, consistent with data in adults and adolescents, Xofluza reduced the length of time that the flu virus continued to be released from the body by more than two days compared with oseltamivir (viral shedding; median time of 24.2 hours versus 75.8 hours, respectively). Full results of the study were presented as a late-breaking abstract during the OPTIONS X 2019 congress in Singapore on Sunday, September 1, 2019 (Abstract #11756).

“Each year approximately one in three children develop the flu, and their less mature immune systems mean they are slower to fight the infection and more vulnerable to complications,” said Sandra Horning, M.D., chief medical officer and head of Global Product Development. “We are committed to developing new, more convenient treatment options for children with the flu and look forward to sharing these data with global health authorities.”

MINISTONE-2 is the first global Phase III study for Xofluza in children. It showed that Xofluza was comparable to oseltamivir in relation to key secondary endpoints, including time to alleviation of influenza signs and symptoms (median 138.1 hours versus 150.0 hours).

This is the fourth positive Phase III study for Xofluza, which has now demonstrated benefit in several populations (otherwise healthy, high-risk, children) and treatment settings (symptomatic, post-exposure prophylaxis). Xofluza is being further studied in an ongoing Phase III development program, including children under one year, severely ill hospitalized people with the flu, and to assess the potential to reduce transmission of the flu from an infected person to healthy people.

About MINISTONE-2 (NCT03629184)

MINISTONE-2 is a Phase III, multicenter, randomized, double-blind study that evaluated the safety, pharmacokinetics and efficacy of one dose of Xofluza compared with oseltamivir in otherwise healthy children aged one to less than 12 years with an influenza infection and displaying influenza symptoms (temperature of 38°C or over, and one or more respiratory symptoms).

Participants enrolled in the study were recruited in parallel into two cohorts: patients aged five to less than 12 years and patients aged one to less than five years. Patients in both cohorts were randomly assigned to receive one dose of Xofluza (2 mg/kg for patients under 20 kg or 40 mg for patients 20 kg or over) or oseltamivir twice a day over five days (dosing according to body weight). The primary endpoint of the study was the proportion of patients with adverse events or severe adverse events up to study day 29. Secondary endpoints included pharmacokinetics, time to alleviation of influenza signs and symptoms and duration of symptoms, including fever.

About Xofluza™ (baloxavir marboxil)

Xofluza is a first-in-class, one-dose oral medicine with a novel proposed mechanism of action that has demonstrated efficacy in a wide range of influenza viruses, including in vitro activity against oseltamivir-resistant strains and avian strains (H7N9, H5N1) in non-clinical studies. Unlike other currently available antiviral treatments, Xofluza is the first in a new class of antivirals designed to inhibit the cap-dependent endonuclease protein, which is essential for viral replication.

Xofluza is currently approved in several countries for the treatment of influenza types A and B in children, adolescents and adults, and in the United States (U.S.) for the treatment of acute, uncomplicated influenza in people 12 years of age and older. In addition, a supplemental New Drug Application (sNDA) for Xofluza as a one-dose oral treatment for people at high risk of complications from the flu is under review by the FDA and a decision is expected by November 4, 2019.

Xofluza is being further studied in a Phase III development program, including children under the age of one (NCT03653364), severely ill, hospitalized people with the flu (NCT03684044), as well as to assess the potential to reduce transmission of the flu from an infected person to healthy people (NCT03969212).

Xofluza was discovered by Shionogi & Co., Ltd. and is being further developed and commercialized globally in collaboration with the Roche Group (which includes Genentech in the U.S.) and Shionogi & Co., Ltd. Under the terms of this agreement, Roche holds worldwide rights to Xofluza excluding Japan and Taiwan, which will be retained exclusively by Shionogi & Co., Ltd.

XOFLUZA U.S. Indication

XOFLUZA is a prescription medicine used to treat the flu (influenza) in people 12 years of age and older who are otherwise healthy, or at high risk of developing influenza-related complications, who have had flu symptoms for no more than 48 hours.

It is not known if XOFLUZA is safe and effective in children younger than 12 years of age or weighing less than 88 pounds (40 kg).

Limitations of Use: Influenza viruses change over time, and factors such as the virus type or subtype, emergence of resistance or changes in viral virulence could diminish the clinical benefit of antiviral drugs. Consider available information on drug susceptibility patterns for circulating influenza virus strains when deciding whether to use XOFLUZA.

Important Safety Information

Do not take XOFLUZA if you are allergic to baloxavir marboxil or any of the ingredients in XOFLUZA.

Before you take XOFLUZA, tell your healthcare provider about all of your medical conditions, including if you:

are pregnant or plan to become pregnant. It is not known if XOFLUZA can harm your unborn baby.
are breastfeeding or plan to breastfeed. It is not known if XOFLUZA passes into your breast milk.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins and herbal supplements.

Talk to your healthcare provider before you receive a live flu vaccine after taking XOFLUZA.

Take XOFLUZA with or without food. Do not take XOFLUZA with dairy products, calcium-fortified beverages, laxatives, antacids or oral supplements containing iron, zinc, selenium, calcium or magnesium.

The most common side effects are diarrhea, bronchitis, nausea, common cold symptoms (nasopharyngitis) and headache.

XOFLUZA is not effective in treating infections other than influenza. Other kinds of infections can have symptoms like those of the flu or occur along with the flu and may need different kinds of treatment. Tell your healthcare provider if you feel worse or develop new symptoms during or after treatment with XOFLUZA or if your flu symptoms do not start to get better.

Please see the XOFLUZA full Prescribing Information for complete safety information.

You are encouraged to report side effects to Genentech by calling 1-888-835-2555 or to the FDA by visiting http://www.fda.gov/medwatch or calling 1-800-FDA-1088.

About Genentech in Influenza

Influenza, or flu, is one of the most common, yet serious, infectious diseases, representing a significant threat to public health. Since 2010, the Centers for Disease Control and Prevention (CDC) estimates that the flu has resulted annually in 9.3 to 49 million illnesses, 140,000 to 960,000 hospitalizations and 12,000 to 79,000 deaths. Although vaccines are an important first line of defense in preventing the flu, there is a need for new medical options for prophylaxis and treatment. Other antiviral medicines have limitations with respect to efficacy, convenience of dosing and resistance. Genentech is committed to addressing the unmet need in this area through its agreement with Shionogi & Co., Ltd. to develop and commercialize Xofluza.

About Genentech

Founded more than 40 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.